Artificial-ice-making apparatus



Jan, 6: 1925.

H. D. POWNALL.

ARTIFICIAL ICE MAKING APPARATUS Filed Jan. 19 ,1922 3 Sheecs-Sheet l y 32 zz 7911 C7; M MY,

Jan, 6. 1925. 1,521,710 H. D. POWNALL ARTIFICIAL ICE MAKING APPARATUS Filed Jan. 19, 1922 s sheets-sheet 2 gnou/Moz Jan. 6. 1925.4 1,521,710

H. D. POWNALL ARTIFICIAL ICE MAKING APPARATUS Filed Jan.' 19, 1922 3 Sheets-Sheet 3 Patented Jan. 6, 1925.

HENRY D. POWNALL, OF CANTON, t01H10.

ARTIFICIAL-ICE-MAKING APPARATUS.

Application filed January 19, 1922. Serial No. 530,411.

To all whom t may concern.'

Be it known that I, HENRY D. PowNALL, a citizen of the United States, residing at Canton, in the county of Stark and State of Ohio, have invented certain new and useful Improvements in Artificial-Ice-Making Apparatus, of which the following is a specification. y

My invention relates to improvements in artificial ice making apparatus. One of its objects is to provide improved means to release the ice from the ice molds when the ice is to be harvested, and to so regulate the temperature and apply the medium for releasing the ice as to avoid fracturing the ice blocks. Another' object is to provide for regulating the temperature of the fresh water to be introduced into the ice molds to refill them irrespective of the initial tem-' perature of the fresh water. Another ob- `ject is to provide for a controllable exchange of heat between the brine employed to release the ice from t-he molds and the fresh water to refill the molds with means controlla-ble by the operator so that uniform results may be obtained through the different seasons of the year. Another object is to provide for independently regulating the temperature of the releasing medium supplied to the different freezing tanks orV units from the same or from independent fresh water storage reservoirs. Another object is to add heat to or subtract heat from the fresh water storage reservoir independently of the normal exchange of heat from the fresh water to the brine employed to release the ice from the molds. Another object is to provide for a plurality of independent circuits of ice releasing medium. Another object is to provide for readily observing and adjusting the temperature of the releasing medium. My invention also comprises certain details of form combination and arrangement, all of which will be fully set forth in the description of the accompanying drawings in which:

Fig. 1 is a plan of a tank room and its artificial ice producing apparatus embodying my invention as applied to an apparatus to produce artificial ice in relatively large quantities.

Fig'. 2, is a central vertical section through a fresh water storage reservoir on line 2 2 of Fig. 3. Y

Fig. 3, is a horizontal section through thc same on line 3-3 of Fig. 2.

Fig. 4 is a sectional detail of lagging or insulation for the fresh water storage res# ervoir.

Fig. 5 is a perspective view of one of the metal rings entering into the construction of the lagging of the fresh water storage reservoir.

Fig. 6 is a diagrammatic view of the warm brine circulating means whereby the warm brine temperature is observable and controllable by the operator.

Fig. 7 is a sectional detail of one of the warm brine by-pass members in position to by-pass a portion of the warm brine.

Fig. 8 is a view similar to Fig. 7 illustrating another position of the by-pass valve.

The accompanying drawings illustrate the preferred embodiment of my invention in which 14C represent brine cooler members of which one or more maybe employed depending upon the capacity of the installation. A series of freezing tank units 15 are preferably arranged upon opposite sides of the brine cooler members and connected respectively with short supply and return cold brine conduits 16 and 17 by means of which a circulation of cold brine through the brine cooler member and a majority of the freezing tank units may be effected by means of the propellers 18. lvVhere an artificial ice making apparatus of large capacity is required as illustrated inFig. 1 two or more brine coolers each with its accompanying series of freezing tanks may be conveniently assembled end to end and a single fresh water storage reservoir 19 employed to refill the ice molds of any one of the freezing tanks. Y

In practice all of the ice molds of any designa-ted freezing tank unit are filled with fresh water at one operation from the storage reservoir 19 through a system of fresh water conduits not shown. Also freezing is started in all the ice molds of a designated freezing tank unit at once and the ice is ready to be all harvested from one freezing tank unit at once. n

The brine in each brine cooler is cooled by direct expansion of a liquiable refrigerant in a directexpansion chamber or conduit located in the interior of the brine cooler of which 20 are the inlets and 21 the outlets. The brine is circulated in contact with the direct expansion chamber and cooled and then under a slight head through the conduits 17 to the respective freezing llt) tanks and then after a circuit through the freezing tank returned to the brine cooler through one of the conduits 1G, the circulation being in large volume and under low head or pressure in order that all of the cold brine may be intimately mixed and all of substantially uniform temperature, and economical of poiver.

Each of the freezing tanks contains a series of vice molds which are semi-permanently located therein and each provided with a 'fresh Water supply conduit by means of Which fresh Water to refill the ice molds from the storage reservoir 19, may be supplied to refill all the ice molds of one freezing tank unit at one operation. The main or trunk fresh Water conduit 22 serves to lead pre-cooled fresh Water from the storage reservoir 19 through branch conduits, not shown, to refill the various ice molds, Which are not specifically illustrated except that one ice mold is located under each of the ice mold lids 24s of Fig. 1.

Then the ice blocks in the respective ice molds of a designated freezing tank unit have been completely frozen and are ready to be harvested, valve levers 25 and 26 flush with the Hoor of the tank room are actuated to close gate valves located on the inside Wall of each freezing tank unit to close the cold brine conduits 16 and 17, and thereby cut o the flow of cold brine from the brine cooler to the designated freezing tank unit until after the ice has been released from the molds and harvested.

n order to release the ice from the ice molds Within a reasonable length of time and Without fracturing the ice in thel molds requires care in the application of the Warming or releasing medium so that its application is uniform and not irregular, and so that the increase in temperature is gradual. In practice a portion of the cold brine from the designated freezing tank unit is removed through a main Warm brine exit conduit 26 and a branch exit conduit 27 and conducted to a coil 28 immersed in the upper portion of the fresh Water storage reservoir 19 Where it is utilized to cool the Warm fresh Water as it enters at the top of the storage reservoir through the fresh Water supply conduit 29 which is supplied With an automatically actuated iioat valve 30 which serves to normally maintain the supply of fresh Water at uniform level in the reservoir 19. Y

-Varm brine, either that removed from the designated freezing tank unit, or a like quantity from another source is then intimately miXed With the cool brine remaining in the designated freezing tank unit to slightly Warm the entire brine contents of said freezing tank unit. This mixing may take place Wholly Within the freezing` tank unit, but is preferably partly effected Within the freezing tank unit, and partly in the brine conduits intermediate of the freezing tank unit and the fresh Water storage reservoir through the use of a brine circulating pump 31 and a brine by-pass 32.

By either method With suitable care and attention to the brine temperatures the main body of brine in the designated freezing tank unit is uniformly and gradually increased in temperature Without any sudden or local application of suflicient heat to fracture the ice, and the ice is freed from the molds Without unnecessary delay. For relatively small installations only a single brine coil 28 is provided in the upper portion of the fresh Water reservoir 19 as shown for instance in Fig. 2, While for larger installations Where one fresh Waterstorage reser voir serves for a large number of freezing tank units I preferably provide a plurality of brine coils 28 as illustrated in Fig. 1, for instance, in Which each brine coil 28 provided With an independent set of couduits and circulating pump, and is connected up to an independent group of freezing tank units. Since there is usually a Wide range of temperature variation in the raw` or fresh Water supplied through the conduits 29 to the reservoir at different seasons of the year, While the brine temperatures are substantially constant through the various seasons, and at different local ities of installation provision is made to artificially increase or decrease the temperature of the fresh vvater in the storage reset voir 19 in o-rder that the ice harvesting operations may proceed uniformly and that fresh Water to refill the ice molds may be provided at the most suitable temperature.

As illustrated in F ig. 2, the fresh Water storage reservoir 19 comprises a tank or container 33 preferably supported upon a concrete foundation 34 and separated therefrom by heat insulating material cork board for instance. ln the upper portion of said tank are located one or more brine coils 28, which as shown in Fig. 2 are all connected at one end to an intake header 39 Which in turn is connected to the main warm brine supply conduit 26. At the opposite ends said coils 28 are connected to a header 37 Which in turn is connected to the main Warm return conduit 88 from which the Warm brine returns tothe particular freezing tank unit through a branch return conduit 39. The several branch Warm brimx conduits 27 and 39 are respectively controlled by cocks 40 and 41 located inside the Wall of the freezing tank units and provided with upwardly projecting stems .2 and heads ll--l -flush With the floor of the tank room, Where they are adapted to be engaged and operated with a key to open and close the cocks when required to harvest the ice. lf desired the coils 28 may be connected to independent angle-iron bracket 47.

warm brine supply and return conduits substantially as illustrated in Fig. 1.

The raw or fresh water supply conduit 29 is provided with a float controlled valve 30 and the supply of fresh water is automatically maintained thereby at a uniform level slightly below the entrance of the overflow conduit 44 which is designed to take care of any excess of fresh water and avoid accidental overiiow of the reservoir 19. The coils 28 are preferably supported upon an openwork fioor 45 carried by joists 46 and an In the upper part of the reservoir 19 I also preferably provide a coil 48 through which steam or warm water may be admitted if necessary to raise the temperature of the fresh water in the upper portion of the reservoir 19; and to thus temporarily prevent interruption of the harvesting operation, as for instance where the supply of fresh water is temporarily of abnormally low temperature.

In the lower portion of the reservoir 19 is located a coil or coils49 provided with an expansion valve 50 and blow-off valve 50 and an eXit conduit 51, whereby a liquefiable refrigerant is adapted to be supplied through the coil 49 to further refrigerate or reduce the temperature of the fresh water in the lower portion of the reservoir 19, over and above the reduction of temperature in the fresh water normally effected by circulating brine through the coils 28. The cool fresh water is withdrawn from the reservoir 19 from time to time to refill the ice molds of the various freezing tank units through the fresh water exit conduit 22. Two or more thermometers 53 and 54, are attached to the upper and lower portions of the reservoir 19so that the temperatures of the fresh water at different heights in the reservoir 19 may be conveniently observed. I am thus enabled to provide in the storage reservoir a column of fresh water of considerable height which is warmer at top than at bottom and normally sufficiently cooled by the brine in coils 28 for use to refill the ice molds, and in which the temperature of the fresh water at both the top and bottom of the reservoir is under control of the operator.

In order to conveniently provide suitable lagging or insulation for the exterior of the reservoir 19, a series of sheet metal loops or annular bands 55 each having an outwardly projecting rib 56, and of greater diameter than the tank 33 are provided and slipped down over the exterior of the tank 33 where they are interposed between she-et metal plates or annular loops 57 so as to support said plates 57 one above the other .to form a jacket about the side walls of the reservoir tank 33. 1 Insulating material 58 such as mineral wool or granulated cork for instance is adapted to be introduced as insulating material between the tank 33 and the plates 57 and loops 55, and said plates 57 and loops 55 are adapted to be conveniently assembled in place one above the other as the filling in of the insulating material 58v progresses until the top of the tank is reached.

lVhere a plurality of independently connected coils 28 are located in the upper portions of the reservoir 19, the temperature of warm brine being supplied simultaneously through different coils toindependent freezing tank units may be independently controlled by the operator and varied without interference with one another to Secure warm brine of different and varying temperatures to meet the requirements in simultaneously harvesting the ice from different freezing tank units.

In order that the. temperature changes may be more readily and uniformly effected and be more completely under the observation and control of the operator, I 4preferably provide a branch warm brine circuit or loop 60 see Figs. 1 and 6, leading from one of the coils 28 in the reservoir 19 through one arm of a by-pass member 32, and circulating pump 31 and thence to a main warm brine conduit 38 and thence by branch conduits 39 and .cocks 40 to a series of freezing tank units 15. The return circuit forthe warm brine is effect-ed from the freezingtank units 15 through the cocks 41, branches 27 and main conduits 26 through the opposite arm 66 of the by-pass member 32 to the opposite end of the brine coil 28 in the reservoir 19. Located in the loop 60 are preferably the valves 61 and 62, and a filter member 63. A tapered three-way cock 64 is located in the arm 66 of the by-pass member 32, so as to be adjusted to direct all or any portion of the brine along the conduit 26 to the coil 28 or to direct all or any portion of the brine through the by-pass passage 67 into the arm 65 and loop 60 as indicated in Figs. 7 and 8. The cock 64 has a stop lug to limit its movement to an arc of approximately degrees, and is provided with a hand lever 68 tov actuate the cock. 7 O and 71 represent thermometers or othertemperature indicators attached respectively tothe arms 65 and 66 of the by-pass 32 whereby the temperature of the brine in the respective arms 65 and 66 may be read and compared with Aeach other and thereby warm brine conditions suitable for releasing the ice without fracture or injury may be attained and maintained or adjusted. noted that in substantially the position shown in Figs. 6 and 7, the operation of the circulating pump 31 is to draw a relatively small volume of warm brine from the coil 28 and to thoroughly miX and incorporate this warm brine with a larger volume kof relativelycold brine taken through one of the cocks 41, and its branch 27 and main conduit 26 to the arm 66 of the bypass and thence through the passage 67 to the arm Where it mingles and is mixed With the Warm brine from coil 28 and both are returned through conduits 38 and 39 and cock 40 and further mingled and mixed with the main body of cooler brine in the freezing tank unit. As the temperature. of the brine in the freezing tank unit `is gradually elevated the cock Ge may be adjusted from time to time to progressively mix an increased volume of' Warm brine from coil 28 with that circulating through the by-pass to and from the freezing tank unit, until finally all of the brine handled by the pump may be passed through the coil'QS and none of it through the passage 67 of the by-pass member 82, as shown in Fig. 8. At the opposite limit of adjustment of the cock 64, all of the brine handled by the pump goes through the passage 67, and none through the coil 28. The temperature indicators 7 O and 7l enable the operator to tell at a glance with certainty the conditions being attained in the freezing tank units, and indicate what adjustment if any of the cock 64 is required.

Where thel by-pass member 32 is omittedas indicated at the top of Fig. l the operator is required to give greater care and attention to the regulation of the Warm brine circulation, preferably by starting the circulating` pump at relatively slow speed and later increasing the speed of the pump as the temperature of the brine in the freezing tank unit rises. Y y

I contemplate employing by-pass members 32 With each of theAcoils 28 illustrated in Fig. l, and When so employed, and also in a less convenient manner as shovvn in the upper portion of Fig. l, the upper Warm portion of a single body of fresh Water may be employed to Warm the brine in a plurality of coils and the various stages of the brine cooling operation and ice releasing operation may be independently developed and carried on in the respective brine Warming circuits.

The apparatus herein illustrated and described is capable of considerable modification Without departing from the spirit and scope of my invention.

What I claim is:

l. An artificial ice making apparatus comprising a brine cooler, a plurality of freezing` tank units each provided With an ice mold, cold `brine conduits leading from said brine. cooler to the respectivefreezing tanks, a member to circulate cold brine from said brine cooler through the respective freezing tanks, members to independently cut on' the supply of cold brine to the respective Vfreezing tanks, a storage reservoir in Which to accumulate and store a supply of pre-cooled fresh Water, a fresh Water precooling compartment provided with a heat exchange member connected by brine conduits with the respective freezing tank units and adapted to exchange heat from the fresh Water to cool brine from one of said freezing' tank units, a member to circulate brine from any one of said freezing tank units to and from said heat exchange member, and conduits from said fresh Water storage reservoir to said respective ice molds, said storage reservoir being of relatively greater capacity than said pre-cooling compartment.

2. An artificial ice making apparatus comprising a brine cooler, a plurality of freezing tank units each provided with an ice mold, cold brine conduits leading from said brine cooler to the respective freezing tank units, a member to circulate cold brine from said brine cooler through the respective freezing tanks, members to independently cut olf the supply of cold brine to the respective freezing tanks, a fresh Water storage reservoir having a lower section in which pre-cooled yfresh Water is accumulated and stored and an upper section in which relatively Warmer fresh Water is pre-cooled and from Which the Vpre-cooled Water gravitates, a heat exchange member loca-ted in thel pre-cooling upper section of said reservoir and connected by brine conduits With the respective freezing tank units and adapted to exchange heat from the relatively Warmer fresh Water to the cool brine from said freezing tank units, a member to circulate brine from any one of said freezing tank units to and from said heat exchange member, and conduits from said fresh Water storage reservoir to said respective ice molds. Y Y

3. An artificial ice making apparatus comprising a brine cooler, a plurality of freezing tank units each provided with an ice mold, cold brine conduits leading from said brine cooler to the respective freezing tanks, a member to circulate cold brine from said brine cooler through the respective freezing tanks, members to indel'iendently .cut olf the supply of cold brine to the respective freezing tank units, a storage reservoir in which to accumulate and store a supply of precooled fresh Water, a heat exchange member located in the upper port-ion of said storage reservoir and connected by brine conduits with the respective freezing tank units and adapted to exchange heat from the fresh Waterin said reservoir to cool brine from one of said freezing tank units, a member to circulate brine from any one of said freezing tank units to and from said heat exchange member, a valvecontrolled by-pass member interposed in the vbrine conduits connecting said heat exchange member with said freezing tank units to enable Warm brine from said heat exchange member to be intimately mixed With cool brine from en e of said llt) lill) i' freezing tank units, and conduits from said fresh Water storage reservoirto the respective ice molds.

t. An artificial ice making appartus comprising a brine cooler, a plurality of freezing tank units each provide-d with an ice mold, means to circulate cold brine from the brine cooler through the respective freezing tank units, a fresh Water conduit system to supply fresh Water to refill each of the ice molds of the respective freezing tank units, means to cut oft' the supply of cold brine from the brine cooler to the respective freezing tank units, a heat exchange member 4in which Warm fresh Water on its Way to refill the ice mold exchanges heat into the brine surrounding one of the ice molds from which the ice is to be released, a warm brine conduit system connecting said heat exchange member With the respective freezing tank units, a valve controlled by-pass in said Warm brine conduit system to enable Warm brine from said heat exchange member to be intimately mixed with cool brine from one of the freezing tank units, and means to create acurrent of brine to and from said heat exchange member through said by-pass member.

5. An artificial ice making apparatus comprising a plurality of freezing tank units each provided with an ice mold, means to circulate cold brine to and from said respective freezing tank units, a fresh Water conduit system to supply fresh Water to refill each of the ice molds of the respective freezing tank units, means to cut off the circulation of cold brine to the respective freezing tank units, means to exchange heat from Warm fresh Water on its Way to refill the ice molds into the brine of one of said freezing, tank units from Which the ice is to be harvested, a Warm brine conduit systcm connecting said heat exchange means With the respective freezing tank units, a valve controlled by-pass in said Warm brine conduit system to enable Warm brine from said heat exchange means to be intimately mixed with cool brine from one of the freezing tank units, and means to circulate brine to and from said heat exchange meansv through said by-pass member.

G. An artificial ice making apparatus comprising a brine cooler', a plurality of freezing tank units each provided With an ice mold, means to circulate cold brine from said brine cooler through the respective freezing tank units, afresh Water storage reservoir having a section in which to accumulate and store a body of pre-cooled fresh Water With which to refill the ice molds and a section to contain relatively Warmer fresh Water, the sections of said reservoir being so related that pre-cooled fresh Water Will automatically separate from the relatively Warmer fresh Water and Seek one 0f Said sections While the relatively warmer fresh Water will automatically separate from the pre-cooled fresh Water and seek the other of said sections, means located in contact with the relatively Warmer fresh Water to pre cool the fresh Water, and means to conduct pre-cooled fresh Water from said fresh Water reservoir to the respective ice molds.

7. An artificial ice making apparatus comprising a plurality of freez'ng tank unitsV each provided with an ice mold, means to circulate cold brine through the respect-ive freezing tank units, means to independently cut off the circulation of cold brine to the respective freezing tank units, a Warm brinev conduit system through which brine from any one of the freezing tank units may be selectively circulated, means to apply heat to the brine in said Warm brine circuit,

means to cause a HOW of brine through said f Warm brine circuit and means to by-pass and mix Warm and cool brine to gradually mix Warm brine with the body of brine in said freezing tank unit to increase the temperature of said body of brine.

8. An artificial ice making apparatus comprising a plurality of freezing tank units each provided With an ice mold, means to circulate cold brine to and from said respective freezing tank units and into contact With the side Walls of said ice molds, means to independently cut oif the circulation of cold brine to the respective freezing tank units, a Warm brine conduit system through Which brine from any one of the freezing tank units may be selectively circulated,l means to apply heat `to the brine in said Warm brine circuit, and circulating means to variably mix vvarmbrine With the body of brine in said freezing tank unit and adjustable to provide a( gradual and accelerated increase in the temperature of said body of brine.

9. An artificial ice making apparatus comprising a plurality of freezing tank units each provided With an ice mold to the side Walls of Which cold brine is applied by circulating cold brine to and from said respective freezing tank units, means to independently cut off the circulation of cold brine to the respective freezing tank units, a Warm brine conduit system through which brine from any one of the freezing tank units may be selectively circulated, a valve controlled by-pass included in said Warm brine circuit, means to apply heat to the brine in said Warm brine circuit, and means to cause a flow of brine through said lWarm brine circuit and by-pass whereby Warm bri-ne is mixed With cool brine in said Warm brine circuit and the resultant is mixed with the body of brine in one of the freezing tank units to rele-ase the ice from the ice mold therein.

l0. An artfcialice making apparatus comprising a plurality of freezing tank units each provided with a plurality of ice molds means to circulate cold brine to and from said respective freezing tank units and into Contact with the side walls of said ice molds, means to cut ofi' the circulation of cold brine to the respective freezing tank units, a fresh water storage reservoir having a section in its lower portion in which cool fresh water accumulates by gravitation to serve as a storage reservoir for pre-cooled fresh water and a section in its upper portion in which relatively warmer fresh water separates by convection from the pre-cooled fresh water, a heat exchange member in contactwith the relatively warmer fresh water in said reservoir, a warm brine conduit system in which said heat exchange member is included and through which brine from any one of the freezing tank units may be selectively circulated'to increase the temperature of the brine in said warm brine conduit system and at the same time reduce the temperature of the fresh water on its way to reiill the ice molds in said freezing tank units, and means to cause a flow of brine through said warm brine conduit system.

1l. An articial ice making appa atus comprising a plurality of freezing tank units each provided with a plurality of ice molds, means to circulate cold brine toand from said respective freezingtank units, means to cut off the circulation of cold brine to the respective freezing tank units, a fresh water storage reservoir having a section in its lower portion in which pre-cooled fresh water tends to accumulate automatically by gravitation to provide an accumulation of pre-cooled fresh water with which to refill the ice molds and a section in its upper portion in which relatively warmer fresh water tends to automatically accumulate and separate from the pre-cooled fresh water by convection, a heat exchange member in contact with the relatively warmer fresh water in the upper portion of said fresh water storage reservoir, a warm brine conduit system in which said heat exchange member is included and through which brine from any one of the freezing tank units may be selectively circulated to increase the temperature of the brine in said warm brine conduit system and at the same time reduce the temperature of the fresh water on its way to refill the ice molds in said freezing tank units, and means to cause a flow of brine through said warm brine conduit system.

l2. An artificial ice making apparatus comprising a plurality of freezing tank units each provided with an ice mold, means to circulate cold brine to and, from said respective freezing tank units, means to cut off the circulation of cold brine to the respective freezingv tank uni-ts, a fresh water cooling and storage reservoir having -a lower section in which pre-cooled fresh water accumulates automatically by gravitation and an upper section in which relatively warmer fresh water automatically accumulates and is separated from the precooled fresh water, a heat exchange member located in the upper portion of said fresh water storage reservoir in contact with the relatively warmer fresh water, a warm brine conduit system in which said heat exchange member is included and through which brine from any one of the freezing tank units may be selectively circulated to increase the temperature of the brine in said warm brine conduit system and at the same time reduce the temperature of the fresh water in `the lower portion of said storage tank,

means to cause a flow of brine through said warm brine conduit system, and means to independently further reduce the temperature of the fresh water in the lower portion of said reservoir before the fresh water is employed to refill the ice molds.

13. An artificial ice making apparatus comprising a plurality of freezing tank units each provided with an ice mold, means to circulate cold brine to and from said respective freezing tank units, Vmeans to cut off the circulation of cold brine to the respective freezing tank units, a fresh water cooling and storage reservoir to supply precooled fresh water to rell said ice molds, a

heat exchange member located in the upper portion of said fresh water storage reservoir, a warm brine conduit system in which said heat exchange member is included and through which brine from any one of the freezing tank units may be selectively circulated to increase the temperature of the brine in said warm brine conduit system and at the same time reduce the temperature of the fresh water in the lower portion of said storage reservoir, means to cause a flow of brine through said warm brine conduit system, means to independently further reduce the temperature ofthe fresh water in the lower portion of said reservoir before the fresh water is employed to refill the ice molds, and means under the control of the operator to temporarily add heat to the fresh water in the upper portion of the fresh f water storage reservoir.

14. In combina-tion with va plurality of freezing tank units connected up in a cold brine conduit system and also in a warm brine conduit system, a fresh water cooling and storage reservoir to provide in reserve a body of pre-cooled fresh water to refill ice molds located in the respective freezing tank units, said reservoir being provided with a heat exchange member located in the upper portion thereof through which brine of the warm brine conduit is to be circulated, and an artificial refrigerating memllt) l Lit) water cooling and storage reservoir, said resi ervoir being provided with a heat exchange member located in the upper portion thereof through which brine of the warm brine conduit is to be circulated, an artificial refrigerating member located in the lower` portion of said reservoir to pre-cool the fresh water in the lower portion of said reservoir independently of said heat exchange member, and a fresh water heating member located in the upper portion of said reservoir and under control of the operator to temporarily add heat to that portion of the fresh water in the upper portion of said reservoir. Y

16. In combination with a plurality of freezing tank units connected up in a cold brine conduit system and also in a warm brine conduit system, a heat insulated fresh water cooling and storage reservoir, said reservoir being provided with a fresh water overflow at the upper end thereof a fresh water exit conduit at the lower end thereof, an automatically valve controlled fresh water supply conduit at the upper end thereof, a heat exchange member in the upper portion thereof through which heat is exchanged from the warm fresh water to brine circulating in said warm brine conduit system, an independent artificial refrigerating member in the lower portion of said reservoir controllable by the operator to pre-cool the fresh water independently of said heat exchange member, and means controllable by the operator to add heat when required to a strata of fresh water in the upper portion of said storage reservoir.

17. An artificial ice making apparatus comprising a plurality of freezing tank units cach provided with an ice mold to the side walls of which cold brine is applied by circulating cold brine to and from said respective freezing tank units, means to cut olf the circulation of cold brine to the respective freezing tank units, a fresh water storage reservoir to provide in reserve a body of pre cooled fresh water to refill said ice molds, a plurality of independent heat exchange members in Contact with which the fresh water is circulated to provide pre-cooled fresh water with which to refill the ice molds, a plurality of warm brine conduit systems each independently connected to one'of said heat exchange members and also to a separate group of freezing tank units. whereby the ice may be independently released and harvested at the same time from a plurality of freezing tank units.

m18. An artificial, ice making apparatus comprising a plurality of freezing tank units each provided with an ice mold, means to circulate cold brine to and from said respective freezing tank units, means to cut ofi' the circulation of cold brine to the respective freezing tank units, a fresh water storage reservoir having a lower section in which precooled fresh water accumulates by gravitation and an upper section in which relatively warmer fresh water accumulates and is separated from the pre-cooled fresh water, a plurality of independent heat exchange members in contact with the relatively warmer fresh water in the upper section of said fresh water reservoir, a plurality of warm brine conduit systems each including main and branch conduits and a brine circulating member and each independently connected to one of said heat exchange members and also to a separate group of freezing tank units, whereby the ice may be independently released and harvested at the same time from a plurality of freezing tank units.

19. An artificial ice making apparatus comprising a plurality of freezing tank units each provided with an ice mold, means to circulate cold brine to and from said respective freezing tank units, means to cut ofil the circulation of cold brine to the respective freezing tank units, a fresh water cooling and storage reservoir to provide in reserve a body of pre-cooled fresh water with which to refill said ice molds, a plurality of independent heat exchange members located in said fresh water storage reservoir and in contact with which the fresh water is circulated to pre-cool the fresh water before refilling the ice molds therewith, a plurality of warm brine conduit systems each including main and branch conduits avvalve controlled by-pass member and a brine circulating; member and each independently connected to one of said heat exchange members and also to a separate group of freezing tank units, whereby the ice may be independently released and harvested at the same time from a plurality of freezing tank units without liability of the ice blocks being fractured.

20. An artificial ice making apparatus comprising a plurality of freezing Qtank units each provided with an ice mold, means to circulate cold brine to and from said respective freezing tank units, means to cut off the circulation of cold brine to the respective freezing tank units, a fresh water cooling and storage reservoir to provide in reserve a body of pre-cooled fresh water with which to refill said ice molds, a fresh water heating member controllable by the operator to heat a strata of fresh water in the upper portion ofsaidfreshwater reservoir, a fresh Water cooling member controllable by, thevoperator to c ool: a strata of, the fresh- Water inthe lower portion of said reservoir, a plurality of independent heat exchange members located in the upper portion off saidi reservoir to normally pre-cool; the fresh` Water` in the lower portion of said' reservoir before it is employed. to refill the ice molds, a plurality of4 Warm brine conduit systems each includingV main. and, branch conduits valve controlled by-pass members and bri-ne circulating members andeach independently connected to one of said heatexchange members and also to a separate group of freezing tank units, whereby the ice may be independently released andl harvested Without liability of being fractured at the same time from a plurality of freezing tank units.

21. An artificial ice making apparatus comprising a plurality of freezing tank units each provided with an ice mold', means to circulate cold: brine to and from said respective freezing tank units, means to cut oli' the circulation of cold brine to the respective freezing tank units, av Warm brine conduit system through which brine from any one of the freezing tank units may be selectively circulated including a heat eX- change member to increase the temperature of the brine circulated through said conduit system, a brine circulating member, a valve controlled by-pass member having a plurality of thermometers to indicate for comparison the temperatures in opposite limbs of said by-pass member, andy Warm brine conduits connecting.v said freezing tank units, heat exchange member, brine circulating member, and by-pass member in operative relation to gradually apply Warmer brine to release the ice in one of said freezing tank units.

In testimony whereof I have axed my signature.

HENRY D. POl/VNALL. 

